Apparently Hitech disagrees and believes the propeller should stop. Was there nothing else wrong?
Sorry - I wasn't critiquing the flight model; rather, no aircraft that I've flown in AH has had the prop stop, while descending, if it has any kind of rotation (unless you blow your radiator), regardless of whether the engine is on or off. That's why it surprised me to see it moving and then... stop. I assumed you had done something specifically to make it stop. If it just stopped on it's own... weird, but that works.